Let’s talk about: Lead Sheet Symbols

Lead-Sheet Symbols: Triads and 7th Chords

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Lead-sheet symbols are a tricky thing to remember. Even I, if I go too long without reminding myself about my sevenths, get them messed up.

On the chart above, you can see the 5 types of 7th chords and the 4 types of triads.

Let’s talk about the types of sevenths:
A major 7th has what would be the root of the chord and the 7th being a half-step apart (i.e., C — B)
A minor 7th has what would be the root and the 7th a whole step apart (two half steps. i.e., C — Bb)
A half-diminished 7th is also one whole step (two half steps)
A fully diminished 7th is three half steps ( i.e., C — A)

These are just the 7ths. The triad is equally important in determining the type of the 7th chord.

Here is an abstracted version of the above chart:
Major Triad + Major 7th = Major 7th Chord (M7)
Major Triad + Minor 7th = Dominant 7th Chord (Mm7 / dom7)
Minor Triad + Minor 7th = Minor 7th Chord (m7)
Diminished Triad + Minor 7th = Half-Diminished 7th Chord (⦰7th)
Diminished Triad  Diminished 7th = Fully Diminished 7th Chord (o7) (Note that “o” is a radial sign)

“Why the white-notes?”
If you spell your sevenths without qualities, the “white-note” chords are their default position. C E G B is a M7,  F A C E is also an M7. G B D F is the only white-note dominant chord, etc etc. They are useful as a memory tool.

What does it look like in two different keys?

7th Chord Qualitiues in C and Bb

Hear it:

Download: 7th Chord Qualities MP3 

Notice how the minor 7th (m7) almost sounds major. This is because of the major chord that exists in the chord when the bass note is removed. C Eb G Bb, remove the C and you have a Eb major triad.

Copyright info for these charts:

7th Chord Chart by Jesse Zylstra is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
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